import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int M = scan.nextInt();
		int []P = new int[M];
		int []Q = new int[M];
		for(int i = 0; i < M; i++) {
			P[i] = scan.nextInt();
			Q[i] = scan.nextInt();
		}
		scan.close();
		int ans = N;
		for(int i = 0; i < M; i++) {
			if(ans == P[i]) {
				ans = Q[i];
			}else if(ans == Q[i]){
				ans = P[i];
			}
		}
		System.out.println(ans);
	}
}